Finding Dulcinea Logo New
Generic selectors
Exact matches only
Search in title
Search in content
Post Type Selectors

On This Day: San Francisco Bubonic Plague Outbreak Begins

Last updated: February 11, 2023

On May 27, 1907, a sailor in San Francisco was diagnosed with bubonic plague. The disease, which prior had been confined to Chinatown, soon spread to all areas of the city.

The Bubonic Plague Outbreak in San Francisco

The plague came to California via a ship traveling from Hong Kong in the summer of 1899. There was a resulting outbreak in 1900, particularly in the city’s Chinatown area, where people lived in close quarters that made for easy transmission of the disease.

A cleaning campaign in Chinatown eventually brought the plague under control in 1904, but a major earthquake in April 1906 brought about a second epidemic that spread outside Chinatown to all parts of the city.

“The disaster created a new urban landscape,” explains the San Francisco Department of Public Health. “Many San Franciscans lived in crowded temporary shelters and cottages in refugee camps. Accumulated garbage and debris created a congenial environment for rats, some of which carried bubonic plague.”

On May 27, 1907, a sailor crossing San Francisco Bay on a ferry was diagnosed with bubonic plague. That summer, “the disease increased with such virulence that it looked for a time as if the city were to be decimated as was mediaeval Europe,” wrote The New York Times in November 1907.

Several unsuccessful attempts to curb the outbreak were made. According to PBS, “commissions and boards formed, fought with the governor, and were disbanded, underfunded, and reformed.”

Meanwhile, scientists were discovering that the plague was carried by pests and rodents. These theories were not widely accepted until 1908, but San Francisco began to solve its problem by controlling the rat population. It collected and killed rats, and by 1909, the city was plague-free.

History of the Plague

Sources in this Story

  • KRON-TV Channel 4 (San Francisco): Into the Fire
  • San Francisco Department of Health: 1906 Earthquake & Fire
  • The New York Times: Stamp Out Plague by Killing Rats
  • PBS: A Science Odyssey: Bubonic plague hits San Francisco
  • Loyola University New Orleans: Plague in the Ancient World: A Study from Thucydides to Justinian
  • The Black Death: Bubonic Plague
  • History News Network: The Shifting Explanations for the Black Death, the Most Devastating Plague in Human History
  • PubMed (Yale Journal of Biology and Medicine): The Pneumonic Plague Epidemic of 1924 in Los Angeles
  • World Health Organization: Plague
  • Centers for Disease Control and Prevention: Information on Plague

The plague is one of the oldest diseases known to man. It is caused by the bacterium Yersinia pestis, which is carried by fleas and small animals such as rodents.

There have been three recorded plague pandemics. The first, known as the Justinian plague, occurred in the sixth century, when the bubonic plague spread through Constantinople and the Byzantine Empire. Though it is difficult to determine the severity of the outbreak due to limited sources, modern historians tend to believe that, at its peak, the plague killed at least 5,000 people a day in Constantinople and killed one-third of its population overall.

The most famous plague epidemic occurred in the 14th century. In 1347, an outbreak of bubonic plague in China reached Sicily by ship; the plague soon spread throughout Italy and Western Europe. Over the next five years, the “Black Death” killed an estimated 25 million people across Europe, about one-third of the population.

Recent scholarship has questioned whether the Black Death was indeed caused by the plague. Several historians and scientists doubt that the bubonic plague, which cannot be spread from human to human, could have spread so quickly through fleas and rodents.

The San Francisco outbreak was part of the third pandemic. It began in China in 1855 and spread to five continents over the next century. It was also responsible for an outbreak in Los Angeles in 1924-5, the last major urban outbreak of the plague.

The third pandemic gave scientists a chance to better study the plague. In 1894, physicians Shibasaburo Kitasato and Alexandre Yersin each identified the bacteria Yersinia pestis.

The Plague Today

There are three forms of the plague: the bubonic, septicaemic and pneumonic forms. The bubonic form is the most common form, spread to humans through flea bites and infects the lymph nodes. In serious cases, the bubonic plague can cause one of the other two more deadly forms to develop.

Bubonic plague victims suffer from “a very painful, usually swollen, and often hot-to-the touch lymph node, called a bubo” and flu-like symptoms such as “fever, headache, and general illness,” according to the Centers for Disease Control and Prevention (CDC). The plague requires immediate treatment with antibiotics.

On average, there are 1,000 to 2,000 cases of the plague every year. According to the latest WHO data, in 2003 there were 2,118 cases of the plague in nine countries, resulting in 182 deaths. More than 98 percent of the cases and deaths occurred in Africa, but the WHO warns that the plague remains endemic in the former Soviet Union, the Americas and Asia. The plague is not found in Australia and has not been active in Europe since World War II.

There are a handful of cases of plague outbreaks in the world every year; the WHO believes that there are others in remote areas that go unreported, and provides a list of recent outbreaks.

Leave a Reply

Your email address will not be published. Required fields are marked *

linkedin facebook pinterest youtube rss twitter instagram facebook-blank rss-blank linkedin-blank pinterest youtube twitter instagram